1. Field of the Invention
The present invention relates to an infrared remote control receiver (IRCR), and more particularly to an IRCR with a semiconductor signal processing device, which is designed to be fabricated using complementary metal oxide semiconductor (CMOS) fabrication processes.
2. Description of the Related Art
An IRCR includes a semiconductor signal processing device having an amplifier therein. Noise reduction characteristic of such an amplifier is an important factor to determine sensitivity of an IRCR. Conventional amplifier in a semiconductor signal processing device of an IRCR is typically fabricated using bipolar junction transistor (BJT) fabrication processes or bipolar complementary metal oxide semiconductor (BiCMOS) fabrication processes to obtain an excellent noise reduction characteristic. A semiconductor signal processing device with an amplifier, which is fabricated by using BJT fabrication processes, is excellent in noise reduction characteristic but is disadvantageous in terms of adjustment of small currents less than 1 nA. Further, an amplifier in a semiconductor signal-processing device must have a large capacitor to stably process signals of several tens of KHz signal band. Accordingly, in the case of fabricating such a semiconductor signal processing device with an amplifier using BJT fabrication processes, the semiconductor signal processing device occupies a large area in a chip and consumes a large amount of powers. Accordingly, the signal processing device has a large chip size. Further, a microcomputer electrically connected to the signal processing device in an IRCR is mostly fabricated using CMOS fabrication processes. Accordingly, it is difficult to combine such a microcomputer mostly fabricated using CMOS fabrication processes and a signal processing device designed to be fabricated using BJT fabrication processes into a single chip because their fabrication processes are not compatible.
Further, an envelope signal detecting circuit in a conventional semiconductor signal processing device of an IRCR generally detects an envelope signal in one direction, a positive direction or a negative direction. However, to improve signal detection efficiency, bi-directionally detected differential envelope signals are needed. To bi-directionally detect envelope signals, two envelope signal-detecting circuits are needed and therefore configuration of such semiconductor signal processing device becomes complicated.